The present invention relates generally to an improved train, and more specifically to articulation assembly between the cars of integral trains and an intermodal integral train for transporting highway vehicles having their own wheels or other types of loads, without wheels, such as containers.
The design of special cars to be used in a railroad system to carry containers or trucks or truck trailers have generally been modifications of existing railroad stock. These systems have not been designed to operate in the normal railway environment which imposes shock loads on the cars during switching and operating periods, and thus, have not taken advantage of the fact that these lighter loads could be designed for if cars were never uncoupled for switching operations. The economy and operation of the lighter weight trains that could thus be designed, as well as economies in the costs of original material were not taken into account.
As integral train can be made up of a number of subtrains called elements. Each element consists of one or two power cabs (locomotives) and a fixed number of essentially permanently coupled cars. The cars and power cabs are tightly coupled together in order to reduce the normal slack between the cars. The reduction of the slack results in a corresponding reduction in the dynamic forces which the cars are required to withstand during the run in and out of the train slack. The reduction of the dynamic forces allows for the use of lighter cars, which allows for an increase in the cargo weight for a given overall train weight and therefore an increase in train efficiency. Additional improvements in efficiency were to be obtained through the truck design and from other sources.
It is well known that when trains go around a sharp curve, the railroad truck must rotate relative to the body to allow the train to negotiate the curve. Various railroad truck constructions have been provided to allow this to happen. Similarly, articulated couplings have been provided between cars to help steer the railroad cars around the turns. These generally have included adjustable linkages connection the cars to each other and laterally displaced to complementarily elongate and contract. In some trains, a common railroad truck has been provided between adjacent cars which constitutes the articulated coupling. The cars are joined to the truck to pivot at a point along their longitudinal axis and rods are provided at both ends of the truck and connected to each of the cars such that the axle of the truck bisects the angle defined by the adjacent lateral axis of the adjacent cars.
An improved articulated coupling for integral trains is described in U.S. Pat. No. 4,718,351 to Engle. The articulated coupling included a center coupling and a pair of side bearings or couplings coaxial along a lateral axis to facilitate yaw and pitch between two cars while restricting roll. The present invention is an improvement on the Engle articulated coupling.
An object of the present invention is to provide an articulation assembly for integral trains.
Another object of the present invention is to provide a slack-free, wear self-compensating articulation assembly between cars.
These and other objects are attained by providing a female coupling along the longitudinal axis of a body to receive a male coupling along the longitudinal axis of an adjacent car wherein the female coupling includes a pair of members each having an arcuate surface forming a portion of an aperture to receive the male coupling. A structure, for example, a wedge, is provided for biasing the first female member along the longitudinal axis towards the male coupling and elements secure the second female member to prevent movement along the longitudinal axis. By supporting both the first and second female members for movement horizontally along the longitudinal axis and allowing the second female member to be removable, the male member may be more readiably positioned in its mated position adjacent to one of the first female member. The first and second female members are of identical structures and each are capable of both receiving a wedge to produce the biasing as well as a pin or other securing elements. The wedge extends vertically and a spring biases the wedge vertically and maintains it on the car. Preferably the wedge is made up of two segments and provides a pin or other structure for mounting shims between the segments if necessary to accommodate for wear over time. The mounting structure for the shims would be a pin threadably received in one of the wedge segments and received in a bore in the other wedge segment.
A method of coupling a pair of cars including the male coupling and the two member female coupling includes positioning the male coupling adjacent to the first female coupling member and positioning the second female member horizontally adjacent to the male coupling. The second female member is then secured to its car and the male coupling is moved into engagement with the secured second female member. A wedge is then positioned between a body portion of the car and the first female member to bias the first female member towards the male coupling. The wedge is inserted vertically and a spring is mounted to the car to bias the wedge vertically.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.